Restrict allowed characters in contact names to match eeID SafeValueValidator rules

[vohmar]

Limit the allowed characters in contact names (e.g., given_names, surname) to align with the validation used in the eeID-manager's SafeValueValidator:

• Allowed:
  • Latin letters a–zA–Z, including extended range \u00C0–\u017E (e.g., Ä, Ö, Õ, Ü, Ž, Š, etc.)
  • Numbers
  • Space
  • The following symbols: /, ', ’, -, .
• Not allowed: Other symbols (e.g., <, >, @, #, etc.)

Implement a whitelist-based check for contact names based on these rules.